Thank you so much for your kindly reply!
I just checked my I797 and found the I94 stub is valid until 2013, which should be fine. Now what about if my current employer don't want pay me before the new transfer starting date? I think I need to go back China even my I94 doesn't expire.
In this case, do I have to go to US embassy and reapply H1b? Or I can just hold my H1b transfer approval stuff and reenter US without visiting US embassy in China?
Thanks again!